Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e4c4a18fdd2d9ece783340f6d55f0aa07a88ea4bdce9422d2f993ce31848fe81' 
  AND token = 'd98cwNdbfkKKYLlFFAf5mGV6Br2WUzHq+zeVPgBdeUk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}